Aptostichus chemehuevi, Bond, Jason E., 2012

Bond, Jason E., 2012, Phylogenetic treatment and taxonomic revision of the trapdoor spider genus Aptostichus Simon (Araneae, Mygalomorphae, Euctenizidae), ZooKeys 252, pp. 1-209 : 117-119

Aptostichus chemehuevi sp. n. Figures 228-235Map 25

Types.

Male holotype and paratype (AP398) from California, San Bernardino County, Pisgah Crater, 34.7465, -116.3755 1, 666m, coll. Norris & Heath 17.ii.1967, deposited in AMNH.

Etymology.

The specific epithet is a noun in apposition taken from the Chemehuevi Band of the Southern Paiute Native American People.

Diagnosis.

Males (Fig. 228) can be diagnosed from all known species of Aptostichus by having many spines on metatarsus I that form two distinct rows and by having a linear row of multiple spines on the prolateral surface of tibia I (Figs 230-234). Males of all other known species of Aptostichus have a single row of very few spines on metatarsus I and/or have very many spines dispersed across the prolateral surface of tibia I or have only three spines composing the row.

Description of male holotype.

Specimen preparation and condition. Specimen collected from pitfall, preserved in 70% EtOH. Coloration faded. Pedipalp, leg I left side removed, stored in vial with specimen. General coloration. Carapace, chelicerae, legs strong brown 7.5YR 4/6. Abdomen uniform pale brown 10YR 7/4, light markings dorsally (Fig. 228). Cephalothorax. Carapace 4.75 long, 4.15 wide, glabrous, stout black bristles along fringe; surface smooth, pars cephalica elevated. Fringe, posterior margin with black bristles. Foveal groove deep, moderately recurved. Eyes on low mound. AER slightly procurved, PER slightly recurved. PME, AME subequal diameter. Sternum moderately setose, STRl 2.91, STRw 2.33. Posterior sternal sigilla moderate in size, positioned toward center, not contiguous, anterior sigilla pairs small, oval, marginal. Chelicerae with distinct anterior tooth row comprising 6 teeth, posterior margin with single row of small denticles. Palpal endites with patch of small cuspules on proximal, inner margin, labium with 1 cuspule, LBw 0.80, LBl 0.44. Rastellum consists of 5 very stout spines arranged along anterior cheliceral margin, not on mound. Abdomen. Setose, heavy black setae intermingled with fine black setae. Legs. Leg I: 4.80, 3.40, 3.20, 1.98, 1.65; leg IV: 4.78, 2.17. Light tarsal scopulae on tarsus, metatarsus legs I, tarsus leg II. Tarsus I with single, slightly staggered row of 13 trichobothria. Leg I spination pattern illustrated in Figures 230, 231; TSp 6, TSr 4, TSrd 7. Pedipalp. Articles stout, lacking distinct spines (Fig. 229). PTw 1.02, PTl 2.17, Bl 1.04. Embolus slender, tapering sharply toward tip, without serrations (Fig. 229).

Variation (10). Cl 4.06-5.63, 4.77 ± 0.13; Cw 3.38-4.75, 4.04 ± 0.11; STRl 2.46-2.91, 2.69 ± 0.05; STRw 1.77-2.49, 2.13 ± 0.06; LBw 0.68-0.83, 0.75 ± 0.02; LBl 0.44-0.56, 0.47 ± 0.01; leg I: 4.19-5.44, 4.74 ± 0.12; 2.81-3.81, 3.30 ± 0.1; 2.79-3.50, 3.14 ± 0.07; 1.65-2.10, 1.86 ± 0.05; 1.53-1.86, 1.66 ± 0.03; leg IV: 4.00-4.88, 4.53 ± 0.09; 1.88-2.25, 2.12 ± 0.04; PTl 1.89-2.37, 2.07 ± 0.05; PTw 0.87-1.08, 0.96 ± 0.02; Bl 0.98-1.20, 1.07 ± 0.02; TSp 5-8, 6.20 ± 0.29; TSr 4-8, 5.20 ± 0.49; TSrd 6-9, 7.70 ± 0.4.

Description of female.

Known only from male specimens.

Material examined.

United States: California: San Bernardino Co.: 29 Palms Joshua Tree National Park Headquarters, 34.1296, -116.0359 3, 602m, J. Freilid 9.ii.1994 [AP601, 1♂, UCR]; Pisgah Crater, 34.7465, -116.3755 1, 666m, Norris & Heath 11.xi.1961 [AP566, 1♂, AMNH], 17.ii.1962 [AP344, 346, 398, 349, 4♂, AMNH], 6.i.1963 [AP345, 397, 2♂, AMNH], 6.i.1967 [AP565, 1♂, AMNH], 1.ii.1961 [AP342, 347, 2♂, AMNH], 25.ii.1961 [AP343, 1♂, AMNH], 11.ii.1961 [AP348, 1♂, AMNH]; Kelso Dunes, 34.9108, -115.7303 3, 770m, D. Weisman 20.xii.1986 [AP340, 1♂, AMNH], V. & B. Roth 4.i.1981 [AP341, 2juv., CAS].

Distribution and natural history.

Aptostichus chemehuevi is known from only three Mojave Desert localities in San Bernardino County (Map 25); despite extensive collecting efforts at the type locality females have never been collected thus little is known of this species natural history. Males appear to disperse during the winter months, November-February. This species is considered to be syntopic with Aptostichus elisabethae .

Conservation status.

Although little information is available, the conservation status of Aptostichus chemehuevi is likely imperiled (also see discussion of Aptostichus elisabethae ) given its paucity of specimens in collections and distribution restricted to three locations.

Species concept applied.

Morphological.